Conventionally known is an information processing device of a swiping type, in which a card is manually swiped in a guide (a card path) for reading information recorded on the card. “Swiping” to be described in this specification means an operation of sliding a card-like recording medium manually along the guide (a card path) of the information processing device.
An information processing device of such a swiping type is equipped with an image scanner for capturing image data by taking an image from a pattern on a card surface, such as a 2D(dimensional) bar code. The image scanner is a reduction-type optical image scanner for example (Refer to Patent Document 1, Japanese Unexamined Patent Application Publication No. 2002-259902, for example). The reason for using such a reduction-type optical image scanner is that a depth of field of the reduction-type optical image scanner is so deep that focusing can be done easily even under condition where a relative distance of the card from a scanning surface changes somewhat as the card is slid (swiped).
Unfortunately, if the reduction-type optical image scanner is applied, a certain length of optical path is required. As a result, the size of the entire device is likely to become large. Particularly, the reduction-type optical image scanner is not suitable for using as an image scanner to be installed in a mobile information processing device that is transferable. Furthermore, being compared with other types of scanners such as a contact-type image scanner, the reduction-type optical image scanner is more expensive, and therefore it is not preferred for an image scanner to be installed in a mobile information processing device that sells at a low unit price.
From the viewpoint described above, a mobile information processing device equipped with not the reduction-type optical image scanner but the contact-type image scanner is now under review. Being compared with the reduction-type optical image scanner, the contact-type image scanner is shallower in depth and compact, and therefore it is suitable for a mobile information processing device.
However, the information processing device equipped with the contact-type image scanner has the following problems.
When being manually swiped along the guide (card path), a card once held by an operator's hand may be charged with static electricity and it passes through the guide (card path). Therefore, the static electricity may be discharged to the image scanner to result in malfunction and breakdown of the image scanner.
To prevent the static electricity charged in the card from being discharged to the image scanner, the guide (card path) may be constructed with any conductive material such as a metal for removal of the static electricity. However, if the entire part of the guide (card path) is constructed with the conductive material, the information processing device becomes heavy. For weight saving, a conductive resin material containing carbon may be used for the guide. However, required for such a construction is a conductive resin material containing carbon that is generally expensive, and the material eventually increases the production cost. Using the conductive resin material only for a bottom of the guide (card path) solves the problems of the weight saving and the production cost. But the card swiped manually may not contact the bottom sometimes, and in such a case the static electricity cannot be removed for sure.
Therefore, there is a need for a processing device for a card-like recording medium that more surely prevents malfunction and breakdown of the image scanner owing to static electricity, while keeping the static electricity charged in the card from being discharged to the image scanner at the time of swiping the card manually.